Abstract: Objective To investigate the influencing factors and prognosis of bacterial infection (BI) in patients with hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF).Methods A total of 128 patients (94 males and 34 females) with HBV-ACLF admitted to our hospital from January 2016 to April 2021 were enrolled. The average age was 52 (40,62) years. BI was defined as patients with one of the followings: spontaneous bacterial peritonitis, pulmonary infection, biliary tract infection or urinary tract infection. The clinical data was analyzed and compared by t test, chi-square test or rank sum test; Multivariate logistic regression analysis was used to investigate influencing factors of BI in patients with HBV-ACLF.Results Among 128 patients with HBV-ACLF, 24 of which without BI (non-BI group) and 104 of which with BI (BI group). The numbers of patients with prophylactic antibiotics use, hepatic encephalopathy (HE), varicose bleeding and hyponatremia in non-BI group were 7 (29.2%), 3 (12.5%), 2 (8.3%) and 4 (16.7%) respectively, which were significantly higher than those in BI group [13 cases (15.5%), 42 cases(40.4%), 28 cases(26.9%) and 57 cases (54.8%), P<0.05]. The scores of white blood cell (WBC), platelet (PLT), albumin (Alb), total bilirubin (TBil), creatinine (Cr), serum sodium, international normalized ratio (INR) and model for end-stage liver disease (MELD) in non-BI group were 5.3 (4.3, 6.8)×10⁹/L, 98 (62, 133)×10⁹/L, (29.5±3.4) g/L, 225.4 (139.5, 92.8) μmol/L, 55 (47, 66) μmol/L, 136 (133,138) mmol/L, 1.9 (1.6, 2.2) and (19.0 2.5), which were significantly higher than those in BI group [7.3 (4.8, 10.5)×10⁹/L, 76 (46, 110)×10⁹/L, (27.7±3.0)g/L, 214.0 (120.6, 314.7) μmol/L, 66 (50, 103) μmol/L, 132 (128, 136) mmol/L, 2.1 (1.7, 2.7) and (23.2±3.1) points, P<0.05]. All the indexes with significant differences were taken as independent variables for BI in patients with HBV-ACLF (assignment 0=not complicated, 1=complicated). Logistic regression analysis showed that HE and MELD score were independent risk factors (P<0.05), and preventive antibiotic use was protective factor (P<0.05). Patients with HBV-ACLF and BI were divided into survival group and dead group according to the survival outcome. The clinical data of age, WBC, Alb, TBil, Cr, serum sodium, INR and MELD in survival group were 48 (40,54) years old, 6.2 (4.1, 9.6) ×10⁹/L, (28.7±3.3)g/L, 59 (47, 86) μmol/L, 134 (130,137) mmol/l, 2.0 (1.7, 2.4) and (20.5±4.8) points, which were significantly higher than those in the dead group [54 (45,62) years old, 8.3 (5.6, 12.0) ×10⁹/L, 228.2 (126.7, 364.0) μmol/L, 78 (55, 116 ) μmol/L, 132 (127, 134) mmol/l, 2.3 (1.8, 2.9) and (25.2±5.9) points, (P<0.05). There were significant differences in HE, variceal bleeding, mechanical ventilation, shock, hepatorenal syndrome and renal replacement therapy between the 2 groups (P<0.05).Conclusion HE and MELD score are independent risk factors of BI in patients with HBV-ACLF. Preventive antibiotics can effectively improve the prognosis, which has important clinical value.

Key words: Hepatitis B virus-associated acute-on-chronic liver failure, Bacterial infection, Prophylactic antibiotics